Return-indication device for electric interlocking systems.



F. B. COREY.

996,460. Patented June 27, 1911.

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v inv'en or Fred B.COY6

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. all whomet may concern:

Be it known that I, FRED B. COREY, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Return-Indication Devices for Electric Interlocking Systems, of which the following is a specification- My invention relates to the control of railway apparatus for controlling traific such as track switches driven by electric motors, and its object is toprovide a novel arrangement of the return indication device which shows that the movement of the track switch or other "apparatus is completed. .In systems of this character, commonly-din wn as electric interlocking systems, the ob retrieves are ordinarily so arranged that the first part of the movement of the control lever energizes the electric motor to drive the switch controlled by thelever. The control lever is arrested, before it has completed its movement, by a catch,'which is released only by the return indication, showing that the movement of the track switch has been completed. The movement of the lever may then becompleted sofas to unlock other le- ,arrange the return indication magnet so that versinterlocked therewith. Since the safety of the system depends largely upon the certainty that the track switch has completed itsmovement when the return indication is ,received it is desirable that the retui'n indi- Cell-i0 l remain unaflected' by any currents except -.tli e return indication current which is to opir iit' i lit has been proposed heretofore, in electric interlocking systems employing directcur- ;rentfor the driving motors, to use alternat- ,i-ngcurrent. for the return indication and to it cannot be affected by direct current as for instance, byfconnecting it to the return indication circu1t through a transformer. Even with such an arrangement there 15 a possi- ;finctuating direct current.

." ;The object of my invention is eiiectively to guard against such a possibility. v i=i.Mywipvention consists in employlng a rotar motor arranged tobe energized bythe return indication current and so connected -'.to;theticatch which stops the lever that the catch can be released only after the motor has device should be so arranged as to- SCBENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A. CORPORATION OF NEW YORK.

RET'U'RN-INDICATION DEVICE FOR ELECTRIC INTERLOCKING SYSTEMS.

Specification of Letters Patent. Patented June 2'? 1911.

Application filed September 24, 1908. Serial No. 454,644.

completed a predetermined plurality of revolutions. With such an arrangement, while a fluctuating current might cause the motor to start, it could not drive it a suiiicient number of revolutions to release the lever.

My invention will best-be understood by reference to the accompanying drawing which shows diagrammatically an electric interlocking system provided with a return indication device arranged in accordance with my invention.

In the drawing A represents a storage battery or other source of current for the driving motors of the system. The terminals of this battery are connected to the bus 4 bars a. n'represents a switch member carrying four contacts 6 tob and actuated by the control lever C.

0 represents a latchv arranged to arrest the control lever C in mid position by engagement with a slot on the lower side of the control lever.

D represents a transformer having two primary windings connected to contacts of the switch member B and a secondary winding connected to the-primary winding of a small rotary motorE. This motor is shown diagrammatically as of the well known induction type, comprising a short circuited rotor e and two primary windings or sets of coils e 6 These windings are connected in parallel, with a non-inductive resistance e in series with the winding 6 so as to give a relative phase displacement to the currents in the two windings and thereby to givethe in the art. The motor 6 carries a pinion which engages with a gear sector e* which is normally in the position shown in the drawings and which, whenever the motor is deenergized, returns by gravity to that position. \Vhen the motor E is energized it rotates in such a direction as to raise the gear sector 6, and after the motor has completed a number of revolutions determined by the relative sizes of the pinionand the gear sector, the gear sector is brought into engagementlwith the latch 0 so as to move the latch out ofengagement with the control lever C, as indicated in dotted lines, thereby permitting the control lever to complete its movement. The relative size of pinion and gear motor a starting torque as is well understood net, which is in turn carried by the shaft 1..

which, while it might cause the motor to move slightly, could not drive it the necessary number of revolutions to release the latch, since each impulse could carry the mo-' tor only a part of a revolution and after each impulse the gear sector would return by gravity to the position shown in the drawings.

My return indication device' is not limited to any particular arrangement of interlocking system, but for the sake of illustration I have shown it in connection with the system described in my earlier application, Serial No. 443,840, filed July 16, 1908, and in order that the operation of the system may be understood without reference to-my earlier application I shall describe the system here. The two: primary windings of the trans- 'former D are connected in series with the control wires f and f F and F represent relays in the controlwires. I

G represents the armature, and g, 'g 'the field windings of an electric motor. This motor is reversible, the field windings being connected for this purpose in the wellknown manner, so that one winding or the other is energized for the opposite directions of rotation of the motor.

H represents a magnetic clutch, the member carrying the energizing winding of the clutch being fast to a shaft I, which drives through suitable connections (not shown) a track-switch indicated diagrammatically at J. The armature h of the clutch isfast to the shaft of the motor armature G. The clutch is shown provided with two concentric windings, either of which may energize it, two windings being used merely to simplify the wiring.

K represents the armature of a small alternating-current generator, which armature is mounted on the shaft of the motor armature. This generator is provided withfield windings his, which are carried on a field mag- When the clutch H is energized, the armature. and field of the small generator are locked together, and no current can be induced in the generator armature. When the shaft I is stationary, the clutch H deenergized, and the motor-armature G running, an alternating voltage is induced in the generator-armature K, which voltage is employed for furnishing the return indication. Collector rings are provided for clutch H,-

' armature K, and field is, as shown.

L L represent switch-contact members,

ed to and moving with the trackswitch.

These contact members carry auxiliary .contacts Z and Z M and M represent a pair of electromagnets connected to the control-wires f and 7",

shown in full lines. In this position of the switch member B, a circuit is closed from the left hand terminal of battery A, through contact 6 through one primary of transformer D, control-wire f, relay F, magnet M, motor field winding g, the inner winding of clutch H, contact member L, generator field winding is, and motor-armature G, to the common main 0;. Relay F, magnet M, clutch-H, motor field winding g, generator field winding is, and motor-armature G are all energized. The motor consequently starts and drives the track-switch, since the clutch connects the two together. Although the generator field k is energized, no current is induced in the generator armature, since the two elements of the generator are locked together by the clutch. As the track switch moves from one position .to the other. member 7' moves from left to right. When the track-switch completes its movement, member j throws the switch members L and L to their other positions. This short circuits member L and through switch .member L to the second collector ring fromathe left on clutch H. Motor-armature G is, therefore, disconnected from the track-switch and runs free. The field of the alternating-current generator is, therefore, stationary, while its armature is driven by the motor. Furthermore, the generator-armature is now connected to line-wire f This circuit maybe traced from the left-hand collector-ring of armature K through the contact of relay F, through auxiliary contacts Z of switch member L,

through magnet winding M and relay F the I lower primary of transformer I), contact 6 resistance R, right-hand bus-bar a and common main 0, to the right-hand collector ring of generator-armature K. The alternating current generated in this armature consequently produces a voltage in the secondary of transformer D to which the primary windings of the motor E are connected. The motor is therefore energized and turns its rotor e in a clockwise direction so as to raise the gear sector 6 and to release the control lever C.- The iovement of the control lever and switch member B ma then be comother direction.

pleted so as to break the circuit of the main motor at contact bl. switch, switch member B is thrown in'the It will be understood that the relays F and F ,are arranged not to respondto the current from the alternating-current generator. They may be so arranged, either by adjusting them to respond only to a predetermined currentrstrength, since the curr'ent from the alternating generator is natusition, magnet M or M is energized to draw the switch members back to their original position. It should be understood that the switch members L and L 'are mechanically connected to' each other, so as to move to- Since the motor E is of a type which will not respond to direct current theinsertion of the transformer D between the .motor winding and the return indication circuit is not necessary, but the use of this'trans formed simplifies the motor connections and for this reason I prefer to employ it.

I do not desire to limit myself to the particulan construction and arrangement of parts shown, but aim to cover in the appended claims all modifications which are Within the scope of my invention. What I claim as new and desire to secure by Letters Patent of the United States, is,-

1. In combination with an electric motor,

a traflic controlling device, operative connections between said motor and device, a return indication circuit, means for producing a current 111 said circuit when sald device is drlven by said motor to a predetermined position, a rotary motor arranged to be energizedby said current, amember adapted to be operated by said rotary motor, andgearing between said rotary motorand said member whereby said member is actuated To reverse the trackv only by a predetermined plurality of revolutions of said motor.

2. In combination with an electric motor, a traffic controlling device, operative'connections'between said motor and device, a return indication circuit, means for producing a current in said circuit when said device is driven by said motor to a predetermined position, a rotary motor arranged to be energized by said current, a pinion driven by said rotary motor, a member having gear teeth meshing with said pinion, and a second member arranged to be operated by the first member after the first member has moved a distance corresponding toa predetermined plurality of revolutions of said motor.

3. In combination with an electric motor, a control lever therefor, a traflic controlling device, operative connections between saidmotor and said device, a return indication circuit, means for producing a current 1n "said circuit when said device is driven by said motor to a predetermined position, a r0- tary motor arranged to be energized by said current, a latch for said control lever, and

operative connections between said rotary motor and said latch comprising gearing arranged to release said latch only after said rotary motor has completed a predetermined plurality of revolutions.

t. In combination with an electric motor,

a traflic controlling device, operative connections between'said motor and said device, a return indication circuit, means for producing in said circuit a current of a character differing from that on which said motor operates when said device isd'riven by' said motor to a, predetermined position, a rotary motor operatively related to said circuit adapted to 'be' energized only by current of said character, a member adapted to be actuated by said rotary motor, and gearing between said rotary motor and said member wherebysaid member is actuated only by a predetermined plurality of revolutions of said motor. I

In' witness whereof, I have hereunto set my hand this 22nd day of September, 1908.

FRED B. COREY.

Witnesses:

BENJAMIN B. HULL, MARGARET E. WOOLLEY. 

